Eddie88,It occured to me you seemed to have possessed the idea that one can arbitrarily pick and choose active or passive voice without logically considering the context. Where are my shoes? Your shoes are being polished - the focus is on the shoe. A machine is polishing his shoes - the focus is on the machine. Besides, a machine can not polish the shoes unless somebody is operating the machine. When we construct an understandable sentence, we must do it in such a way that the reader can see iin their mind without questions.

Um, I didn't write any of these sentences myself, including the first one; I extract them from various sites.

The person who wrote the first sentence said that it came up incorrect on Word. I see nothing wrong with it, other than the possible misplaced modifier. However, I think it is relatively clear that the phrase modifies 'them.'

But if you can see anything wrong with the sentence, please do share it.